[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

20000918: McIDAS images via LDM; ldm-mcidas pnga2area decoder

>From: Dave Dempsey <address@hidden>
>Organization: SFSU
>Keywords: 200009181632.e8IGWHb04705 ldm-mcidas PNG pnga2area

Dave,

I was somewhat suprised by your email to Harry yesterday:

>Sorry to inflict that message on you--I thought I'd figured out the
>problem before I sent the message to you. Turns out that we had a
>separate "request" line in our ldmd.conf file for MCIDAS images, and
>the machine was specified by IP address rather than machine name and I
>missed it.
>
>However, after correcting that oversight, we seem to be getting MCIDAS
>images but no longer saving them:
>
>   Data reception log example:
>
>20000918125014  MCIDAS        unidata.ssec.wisc.edu         16    5047002     
>  16.50   55@3813 20000918125021
>
>An example line in pqact.conf is:
>
>MCIDAS ^LWTOA3.*DIALPROD=U9
>       PIPE    -close /usr/local/wxp/bin/mc2area -p /h/data/mcidas/gwvis %y%m%
> d%H_svi.mca
>
>This has worked fine for years but suddenly stopped working after we
>switched to sunny89. There are no error messages in our LDM logs, and
>we're getting all of our other data.
>
>Thinking that the invocation of the WXP program "mc2area" might have
>been the problem, I added an alternative:
>
>MCIDAS ^LWTOA3.*DIALPROD=U9
>       FILE    data/mcidas/gwvis/(\1:yy)(\1:mm)\1\2_svi.mcu
>
>This produces zilch also. The problem applies to all 11 types of MCIDAS
>images, for each of which we have a separate pqact.conf entry.
>
>To your knowledge, has the header line for MCIDAS images been affected
>in some way by the switch to sunny89, or a change implemented 
>coincident with the switch, that might make our pqact.conf entries
>obsolete?
>
>-- Dave

Since I had seen you download the ldm-mcidas package on July 27, I
figured that you were on top of the datastream change that I had been
announcing to the ldm-users, gembud, and mcidas-x email lists since
June.  This change went into effect at 18 Z last Friday; this is why
you are no longer decoding Unidata-Wisconsin datastream imagery.

I sent out personal emails to all sites that had NOT downloaded the
latest ldm-mcidas release at the beginning of last week, and I had been
working with a number of these folks, helping them get their decoding setup
before the cessation of delta-encoded (LWTOA3 header) images on
last Friday.

Anyway, I wanted to see if you need help in converting your pqact.conf
entries that used LWTOA3 over to use of the new PNG compressed decoder
pnga2area.  From the one example of what you were using above, I can
offer the following example replacement:

change:

MCIDAS  ^LWTOA3.*DIALPROD=U9
        PIPE    -close /usr/local/wxp/bin/mc2area -p /h/data/mcidas/gwvis 
%y%m%d%H_svi.mca

to:

MCIDAS  ^pnga2area Q1 U9 (.*) (.*) (.*) (.*) (........) (....)
        PIPE    -close
        /usr/local/ldm/decoders/pnga2area
        -a /usr/local/ldm/etc/SATANNOT -b /usr/local/ldm/etc/SATBAND
        /h/data/mcidas/gwvis/%%y%%m%%d%%H_svi.mca

This assumes:

o you installed pnga2area in /usr/local/ldm/decoders
o you copied the SATANNOT and SATBAND files from the etc directory of
  the binary ldm-mcidas release (the src/decoded directory of the source
  ldm-mcidas release) to the /usr/local/ldm/etc directory
o you want the files named from information in them (year, month, day, hour)

***** NOTE *****

Note the use of '%%' in the action above.  The LDM will interpret the
first '%' as nothing (since there is a second '%') and pnga2area will
interpret the second.

You will need one entry for each image in the broadcast, but you must
already have these as mc2area actions.

Please let me know if you have any questions about the conversion of
your action to the pnga2area action.  For more information on what
pnga2area is able to do with regards to output file naming, please
either review the pnga2area man page, pnga2area.1; run pnga2area with
no options or the '-h' flag; or review the ldm-mcidas web pages at:

http://www.unidata.ucar.edu/packages/mcidas/mcidd

Tom